Garage Conversion to Living space

[UCM_STL11]

Hello all,

I know garage conversion sometimes sound cheap and ridiculous but you have to understand the situation. We currently have a two car 21x21 attached garage normal 70's ranch style home. We also have a 3 car oversized detached garage/shop which is across the driveway a bit. Our living area quarters are very small in this house and we want to convert the attached garage into living space as the garage shares out living room and kitchen wall that will be knocked down, floors raised to match, windows added and everything to make area feel like it was never a garage. we do want to build another garage with breezeway so we still have "attached" garage and all the kids toys can stay out of my area I already made a separate thread on that topic so my question is:

When enclosing the current two garage doors openings what is the correct way to go about the missing foundation in the opening? I do not want to just put wood right on ground. I am thinking of cutting that section of garage floor out and digging down to pour my footing for my wall to sit on, how deep should I go if there is not a footing below garage floor in the opening? should I epoxy in rebar to the existing foundation and new concrete. Essentially the wall will not be load bearing because I will not be removing the garage header. Sorry for the long post, I have been trying to plan on this for a long time and want to do it right.

 

[Falcon67]

So you answered your own question more or less - the over door beam is in place, the "patch" is just a partition wall. Don't over think it. Construction adhesive will stick the base plate of the fill-in permanently to the existing slab. You parked a car on that surface, the partition you are installing you can lift by yourself.

 

[6768rogues]

How you build it depends on where you are and your climate.

 

[UCM_STL11]

So you answered your own question more or less - the over door beam is in place, the "patch" is just a partition wall. Don't over think it. Construction adhesive will stick the base plate of the fill-in permanently to the existing slab. You parked a car on that surface, the partition you are installing you can lift by yourself.

I agree and have thought of that as well. The one thing that is keeping me from attaching the base plate straight to the existing slab is the outside appearance and water issues. Although I have siding on outside and could possibly run a half brick wall since the front of the house is brick... I live is suburb of St. Louis so there is a lot of rain and snow.

 

[ducksface]

Illegal in some places.
Nothing anyone says here will change your cc&r and code requirements.

 

[kbs2244]

You are going to need a permit for this project since you are increasing the "loving area" of the home.
All you construction questions can be answered by your building dept.

What you are doing is very common.
There are whole subdivisions of post WW II homes that have gone through this.

 

[ard]

I agree and have thought of that as well. The one thing that is keeping me from attaching the base plate straight to the existing slab is the outside appearance and water issues. Although I have siding on outside and could possibly run a half brick wall since the front of the house is brick... I live is suburb of St. Louis so there is a lot of rain and snow.

Agree.

You have this conversion plus a new garage, plus a connecting conditioned space between them- all in the works with this project, yes? (Reading other threads)

It will be a significant set of plans for the building department- but I get the sense you, like me, want to have as much 'down on paper' so you don't get treated like a ***** when you walk in.

Given that you will be pouring concrete for the other stuff (connecting conditioned space in a new structure btween garage and home) I'd cut the slab, jackhammer out the tell-tale driveway, and create a stem wall to match the existing home/wall.

You do know that garage is (should be) sloped, so any floors will need work.

Also, you say you will be extending floor joists out into the two car bay- remember these need to sit ON something- like piers or a foundation. You may need to create a new 'bearing wall' at the end of these joists. Like cutting out slab, digging and pouring a footing.

Sounds like fun. I assume you already have drawn plans for the home AS IT EXISTS. Get copies made at Kinkos and go to town with sketches. I don't do it for a living, so I will work through plans, sketches and ideas for months....

 

[matt_i]

Personally I'd be a fan of a poured wall, doweled into the existing footings in some way to preserve alignment. One school of thought would say go as deep as the existing footings, but as you pointed out its just supporting the "filler wall". I think I'd go 24" deep and match the width and height of existing, place rebars inside the new footing to keep it all together as well.

 

[Falcon67]

I agree and have thought of that as well. The one thing that is keeping me from attaching the base plate straight to the existing slab is the outside appearance and water issues. Although I have siding on outside and could possibly run a half brick wall since the front of the house is brick... I live is suburb of St. Louis so there is a lot of rain and snow.

You could pour a curbing of sorts across the door opening(s) to match the existing level of the wall plates, then use some kind of sealer+membrane over that to prevent water intrusion. TO make the change completely invisible, you'd need to chip into the existing brick and carry the same color brick across the opening. That would be more work but certainly create a much better/professional front elevation. Most people around here just wall up the opening and install exterior siding. On a drive by, it's easy to see there used to be a garage door in that space lol. Very few go to the effort to integrate the change into the style of the house, mostly because that tends to be done in older less expensive 2 BR 1 or 2 bath type 50's builds with small rooms and no space for growing family.

As for a footer, you might find by probing that the front lip of the openings are thicker than you'd think in order to prevent cracking in that area. On the slab-on-grade stuff here, I see about a 6" x 6 or 12 wide ditch that runs under the area where the garage door would land.